Alex bernstein



(No Model.)

A. BERNSTEIN.

INCANDESOENT ELECTRIC LAMP.

No. 273,704. Patented Mar. 13,1883.

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N4 PETERS. Pholwhlhngnphen Washington, D. c

UNITED STATES PATENT OFFICE.

ALEX BERNSTEIN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE BERN- STElN ELECTRIC LIGHT MANUFACTURING COMPANY, OF SAME PLACE.

INCANDESCENT ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 273,704, dated March 13, 188?.

Application filed January 4, 1883. (No model.)

To all whom it may concern Be it known that I, ALEX BERNSTEIN, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain Improvements in Incandescent Electric Lamps, of

which the following is a specification.

1 My invention relates to improvements in incandescent electric lamps; and its object is a special construction of such lamps whereby 1o thedifierentexpansions and contractions which necessarily occur in them are prevented from exercising any detrimental efiect on the carbon or other light-giving conductor.

To this end my invention consists in attach- 1 ing the said light-giving conductor, which is preferably made of carbon, to theleading-in wires in such a way as to allow free and full play in every direction, it thus being enabled to respond to any change,whether of exten- 2o sion or contraction, however slight.

. In incandescent lamps as heretofore manufactured the attachments of the carbon filaments are subject to serious disadvantage from theirliabilit-y of disruption, arising fromirregular expansion'and contraction, and from this cause many of the lamps have not the durability that might reasonably be expected. These unequal expansions usually occur when the lamps are first lighted or when they are 0 extinguished. They are also liable to occur when there is a sudden increase or diminution in the amount of electricity passing in the circuit, however such irregularity may be caused. The carbon strips,being held rigidly at one or 3 5 both ends by the supporting-wires, tend to expand on cooling and to contract on being heated, and unless there is some means of allowing for this expansion and contraction the light-giving conductor is in great danger of being fractured. By my method of constructing incandescent lamps the difficulty arising from unequal expansion is entirely obviated.

Referring to the drawings which form a part of this specification, in which similar letters 4 5 are used to designate corresponding parts, Figure 1 represents a lamp in which a hollow cylindrical carbon is employed, as described in Letters Patent issued to me on the 30th day of January, 1883. Figs. 2 and 3 represent lamps in which thin carbon strips or filaments are employed as the light-giving part.

In lamps as heretofore made the carbon has been either rigidly attached to both leading-in wires or attached rigidly to one wire and flexibly to the other; but in the construction which 5 I describe herein the connection between the carbon and the conducting-wires is made by suspending the carbon from the said leadingin wires by means of flexible supports, each consisting of a number offine wires attached at their lower ends to the light-givingconductor.

In the lamp shown in Fig. 1, (which may be made in the form of the well-known incandescent lamp patented in England November 4, 1845, by Edward A. King, and popularly designated as the Starr-King lamp, when used for submarine illumination as described in the said specification of King, or which may be constructed in any desired form,) F is the glass inclosing-bulb, which, as usual, is, before sealing, exhausted of its air. A and B are the conducting orleading-in wires for conveying the electricity to and from the light-giving conductor, and C is the said light-giving conductor, which is suspended from the two conducting-wires by means of two flexible conductors, D and E, which are placed at its ends, and which are composed of a large number of small wires.

In Fig. 1 the light-giving conductor is ahollow cylinder of carbon provided at each end with and resting in solid carbon blocks G, which, by means of short wires W, connect with the flexible conductors, the blocks G, as well as thelight-givingpartC, being suspended 8 5 by the flexible conductors from the leadingwires A B. In Figs. 2 and 3 the same construction is shown as applied to acarbon strip or filament, which may be of any desired shape. These wires are flexible, and the number used 0 is large enough to admit of a free passage of the electric current-t. 0., their combined resistance shall not be greater than the resistance of the same length of one of the conducting-wires A. These fine wires, being very flexi- 9 5 ble, readily admit of any elongation or contraction ofthe carbon filamentdue to any cause.

The glass bulb and conducting-wires may expand, while the light-giving carbon may contract, or vice versa, without bringing any strain whatsoever upon the carbon.

I do not, of course, limit myself to the use of flexible wires as a mode of suspension, since it is evident that a metallic chain would subserve the same purpose, and

I claim 1. In incandescent electric lamps, a lightgiving conductor suspended from the leadingin or conducting wiresinside thebulb by means of two flexible conductors interposed in the circuit between the said leading-in or conducting wires and the light-giving conductor, as described.

2. In an incandescent electric lamp, a lightgiving conductor consisting ofa hollow cylindrical carbon suspended from the leading-in wires by means of flexible conductors, the said flexible conductors being entirely within the bulb and each formed of a number of smaller wires maintained separate from one another and united on one side with the light-giving 20 body and on the other side with the leading- In testimony whereofl have signed myname ,.to this specification, in the presence of two subscribing witnesses, this 30th day of December, 1882.

ALEX BERNSTEIN. Witnesses:

I J. H. OHEEVER,

GEO. WILLIS PIERCE. 

